The present invention relates to magnetic printing media and, more particularly, to novel apparatus and methods for fabricating a continuous belt of magnetic material for use in a magnetic printer.
A magnetic printer of the type forming latent magnetic images on a belt of magnetizable material, typically requires that the magnetic belt form a continuous loop frequently having widths on the order of 20 to 30 inches. The belt, typically fabricated with a coating of a ferromagnetic oxide upon a supporting layer of a plastic material, such as Mylar.sup.TM and the like, requires that: the belt have the same loop circumference from one belt edge to the other, as a conical shape must be avoided to assure adequate tracking when the belt is run at high speed; that a bond of adequate strength be made at any splice occurring in the belt, typically having at least one splice where the tape has been drawn into itself to form the loop, to assure that sufficient tension can be applied to the belt to provide adequate contact between the belt material and a magnetic printing head over which the belt must pass for image formation; the tape surface be smooth at such a splice, whereby substantially no inking material is retained, in either mechanical or electrostatic manner, along the line of the splice; the thickness of the belt at the splice should not vary significantly from the thickness of the remainder of the belt, whereby little or no variation in spacing between confronting surfaces of the magnetic printing head and the magnetic belt is achieved, to assure uniformity of magnetic field penetration and, hence, of printing density; continuity of the magnetic surface of the belt must be maintained, to avoid either gaps or magnetic pick-up, for magnetized continuity; and, if the belt is to be tracked on the printer, suitable driving or tracking webs on the outermost edges of the fabricated group of magnetic belts may be added.
Methods and apparatus for forming continuous magnetic printing belts, having all of the above-described characteristics do not appear to be presently available.